JVC LT-17D50BK Service Manual

SERVICE MANUAL
WIDE LCD PANEL TELEVISION
YA22320055
LT-17D50BK
VCR DVDTV
MENU
BACK
P
PC
TV
TABLE OF CONTENTS
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
COPYRIGHT © 2005 Victor Company of Japan, Limited
No.YA223
2005/5
SPECIFICATION
Items Contents
Dimensions ( W × H × D ) 46.5cm × 37.0cm × 20.0cm [Included stand]
46.5cm × 32.6cm × 7.2cm [TV only]
Mass 6.0kg [Included stand]
5.0kg [TV only]
Power Input AC100 to AC240 V, 50 Hz
Power Consumption 56W (Standby: 3.0W)
TV RF System CCIR B/G, I, D/K, L
Colour System PAL / SECAM / NTSC 3.58 / NTSC 4.43 (NTSC: EXT only).
Stereo System A2 (B/G, D/K), NICAM (B/G, I, D/K, L)
Teletext System FLOF (Fastext), TOP, WST (World Standard System)
Receiving Frequency VHF
Intermediate Frequency VIF
Colour Sub Carrier Frequency
LCD panel 17V-inch wide aspect (15:9)
Screen Size Diagonal : 43.3cm (H:37.1cm × V : 22.3cm) Display Pixels Horizontal : 1280 dots × Vertical : 768 dots (W-XGA)
Audio Power Output 5W + 5W(10% THD)
Speaker 3.4cm, round type × 2 Aerial terminal (VHF/UHF) F-type connector, 75 unbalanced, coaxial EXT-1 / EXT-2 (Input / Output) 21-pin Euro connector (SCART socket ) × 2
EXT-3(Input) Component Video
625p / 525p / 625i / 525i
EXT-4 (Input) S-Video
PC (RGB) Input D-sub 15pin × 1
PC AUDIO input 3.5mm stereo mini jack × 1 Audio output 500mV (rms), Low impedance, RCA pin jack × 2
Subwoofer output More than 0 to 1000mV (rms) (+2.2dBs), low impedance (80Hz when modulated
Headphone 3.5mm stereo mini jack × 1 Remote Control Unit RM-C1860 (AA/R6 dry cell battery × 2)
SECAM
47MHz to 470MHz
UHF
470MHz to 862MHz
CATV
116MHz to 172MHz / 220MHz to 469MHz
38.9MHz(B/G, D/K, I)
SIF
33.4MHz(5.5MHz:B/G) / 32.9MHz(6.0MHz:I) / 32.4MHz(6.5MHz:L,D/K)
PAL
4.43MHz
4.40625MHz / 4.25MHz
NTSC
3.58MHz / 4.43MHz
RCA pin jack × 3 Y : 1V (p-p), Positive (Negative sync provided), 75 Cb/Cr : 0.7V(p-p), 75
Audio
500mV(rms) (-4dBs), high impedance, RCA pin jack × 2 Mini-DIN 4 pin × 1
Y: 1V (p-p), Positive (Negative sync provided), 75 C: 0.286V (p-p) (Burst signal), 75
Video
1V (p-p), Positive (Negative sync provided), 75 , RCA pin jack × 1
Audio
500mV (rms), High impedance, RCA pin jack × 2
R/G/B : 0.7V (p-p), 75
HD / VD : 1V (p-p) to 5V (p-p), high impedance < Available signal >
VGA : 640 pixels × 480 pixels (Horizontal : 31.5kHz / Vertical : 60Hz) XGA : 1024 pixels × 768 pixels (Horizontal : 48.4kHz / Vertical : 60Hz)
100%), RCA pin jack × 1
Design & specifications are subject to change without notice.
1-2 (No.YA223)
SECTION 1
PRECAUTION
1.1 SAFETY PRECAUTIONS
(1) The design of this product contains special hardware,
many circuits and components specially for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be performed by qualified personnel only.
(2) Alterations of the design or circuitry of the products should
not be made. Any design alterations or additions will void the manufacturer's warranty and will further relieve the manufacturer of responsibility for personal injury or property damage resulting therefrom.
(3) Many electrical and mechanical parts in the products have
special safety-related characteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the parts list of Service manual. Electrical components
having such features are identified by shading on the schematics and by ( ) on the parts list in Service manual. The use of a substitute replacement which does
not have the same safety characteristics as the recommended replacement part shown in the parts list of Service manual may cause shock, fire, or other hazards.
(4) Don't short between the LIVE side ground and
ISOLATED (NEUTRAL) side ground or EARTH side ground when repairing.
Some model's power circuit is partly different in the GND. The difference of the GND is shown by the LIVE : ( ) side GND, the ISOLATED (NEUTRAL) : ( ) side GND and EARTH : ( ) side GND. Don't short between the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND and never measure the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND at the same time with a measuring apparatus (oscilloscope etc.). If above note will not be kept, a fuse or any parts will be broken.
(5) When service is required, observe the original lead dress.
Extra precaution should be given to assure correct lead dress in the high voltage circuit area. Where a short circuit has occurred, those components that indicate evidence of overheating should be replaced. Always use the manufacturer's replacement components.
(6) Isolation Check (Safety for Electrical Shock Hazard)
After re-assembling the product, always perform an isolation check on the exposed metal parts of the cabinet (antenna terminals, video/audio input and output terminals, Control knobs, metal cabinet, screw heads, earphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.
a) Dielectric Strength Test
The isolation between the AC primary circuit and all metal parts exposed to the user, particularly any exposed metal part having a return path to the chassis should withstand a voltage of 3000V AC (r.m.s.) for a period of one second. (. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance rated up to 120V, and 3000V AC (r.m.s.) to an appliance rated 200V or more, for a period of one second.) This method of test requires a test equipment not generally found in the service trade.
b) Leakage Current Check
Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Using a "Leakage Current Tester", measure the leakage current from each exposed metal part of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground (water pipe, etc.). Any leakage current must not exceed 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.2mA AC (r.m.s.).
Alternate Check Method
Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Use
an AC voltmeter having 1000 per volt or more sensitivity in the following manner. Connect a 1500 10W resistor paralleled by a 0.15µF AC-type capacitor
between an exposed metal part and a known good earth ground (water pipe, etc.). Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75V AC (r.m.s.). This corresponds to
0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.3V AC (r.m.s.). This corresponds to 0.2mA AC (r.m.s.).
AC VOLTMETER (HAVING 1000 /V, OR MORE SENSITIVITY)
0.15 F AC-TYPE
GOOD EARTH GROUND
1500 10W
PLACE THIS PROBE ON EACH EXPOSED ME TAL PAR T
(No.YA223)1-3
1.2 INSTALLATION
1.2.1 HEAT DISSIPATION
If the heat dissipation vent behind this unit is blocked, cooling efficiency may deteriorate and temperature inside the unit will rise. The temperature sensor that protects the unit will be activated when internal temperature exceeds the pre-determined level and power will be turned off automatically.Therefore, please make sure pay attention not to block the heat dissipation vent as well as the ventilation outlet behind the unit and ensure that there is room for ventilation around it.
1.2.3 INSTALLATION REQUIREMENTS
To ensure safety in an emergency such as an earthquake, and to prevent accidents, ensure that measures are taken to prevent the TV dropping or falling over. Use the supplied screws to firmly attach the supplied hooks (OPTION) to the back of the TV, and use commercially available cord to fix the TV to rigid components such as walls and columns.
Wall
Ventilation hole
1.2.2 INSTALLATION REQUIREMENTS
Ensure that the minimal distance is maintained, as specified below, between the unit with and the surrounding walls, as well as the floor etc.Install the unit on stable flooring or stands.Take precautionary measures to prevent the unit from tipping in order to protect against accidents and earthquakes.
100 mm
100 mm
100 mm
100 mm
TV
AV
MENU
P/ch
50 mm
Hook
TV Stand
It fixes in a band.
*Diagram differs from actual appearance.
1.2.4 NOTES ON HANDLING
(1) WHEN TAKING UNIT OUT OF A PACKING CASE
When taking the unit out of a packing case, do not grasp the upper part of the unit. If you take the unit out while grasping the upper part, the LCD PANEL may be damaged because of a pressure. Instead of grasping the upper part, put your hands on the lower backside or sides of the unit.
(2) AS FOR PRESSING OR TOUCHING A SPEAKER
Be careful not to press the opening of the speaker in the lower part of the unit and around them since the decorative sheet on the surface of the openings may be deformed.
1-4 (No.YA223)
1.3 HANDLING LCD PANEL
1.3.1 PRECAUTIONS FOR TRANSPORTATION
When transporting the unit, pressure exerted on the internal LCD panel due to improper handling (such as tossing and dropping) may cause damages even when the unit is carefully packed. To prevent accidents from occurring during transportation, pay careful attention before delivery, such as through explaining the handling instructions to transporters. Ensure that the following requirements are met during transportation, as the LCD panel of this unit is made of glass and therefore fragile:
(1) USE A SPECIAL PACKING CASE FOR THE LCD PANEL
When transporting the LCD panel of the unit, use a special packing case (packing materials). A special packing case is used when a LCD panel is supplied as a service spare part.
(2) ATTACH PROTECTION SHEET TO THE FRONT
Since the front (display part) of the panel is vulnerable, attach the protection sheet to the front of the LCD panel before transportation. Protection sheet is used when a LCD panel is supplied as a service spare part.
(3) AVOID VIBRATIONS AND IMPACTS
The unit may be broken if it is toppled sideways even when properly packed. Continuous vibration may shift the gap of the panel, and the unit may not be able to display images properly. Ensure that the unit is carried by at least 2 persons and pay careful attention not to exert any vibration or impact on it.
(4) DO NOT PLACE EQUIPMENT HORIZONTALLY
Ensure that it is placed upright and not horizontally during transportation and storage as the LCD panel is very vulnerable to lateral impacts and may break. During transportation, ensure that the unit is loaded along the traveling direction of the vehicle, and avoid stacking them on one another. For storage, ensure that they are stacked in 2 layers or less even when placed upright.
1.3.2 OPTICAL FILTER (ON THE FRONT OF THE LCD PANEL)
(1) Avoid placing the unit under direct sunlight over a
prolonged period of time. This may cause the optical filter to deteriorate in quality and COLOUR.
(2) Clean the filter surface by wiping it softly and lightly with a
soft and lightly fuzz cloth (such as outing flannel).
(3) Do not use solvents such as benzene or thinner to wipe the
filter surface. This may cause the filter to deteriorate in quality or the coating on the surface to come off. When cleaning the filter, usually use the neutral detergent diluted with water. When cleaning the dirty filter, use water-diluted ethanol.
(4) Since the filter surface is fragile, do not scratch or hit it with
hard materials. Be careful enough not to touch the front surface, especially when taking the unit out of the packing case or during transportation.
1.3.3 PRECAUTIONS FOR REPLACEMENT OF EXTERIOR PARTS
Take note of the following when replacing exterior parts (REAR COVER, FRONT PANEL, etc.):
(1) Do not exert pressure on the front of the LCD panel (filter
surface). It may cause irregular COLOUR.
(2) Pay careful attention not to scratch or stain the front of the
LCD panel (filter surface) with hands.
(3) When replacing exterior parts, the front (LCD panel) should
be placed facing downward. Place a mat, etc. underneath to avoid causing scratches to the front (filter surface).
(No.YA223)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 FEATURES
T-V LINK
When you have a T-V LINK compatible VCR connected to the EXT-2 Terminal on the TV,it is easier to set up the VCR and to view videos.
ZOOM
This function can change the screen size according to the picture aspect ratio.
2.2 MAIN DIFFERENCE LIST
Items LT-17C50BU LT-17C50SU LT-17C50BU/Z LT-17C50SU/Z LT-17C50BJ LT-17C88SJ
CABINET COLOUR BLACK SILVER BLACK SILVER BLACK SILVER
POWER CORD EU type(2-pin )
SWE Type(3-pin )
EU type(2-pin )
2.3 21-PIN EURO CONNECTOR (SCART) : EXT-1 / EXT-2
Pin No. Signal designation Matching value EXT-1 EXT-2
1 AUDIO R output
2 AUDIO R input
3 AUDIO L output
4 AUDIO GND Used Used
5 GND (B) Used Used
6 AUDIO L input
7 B input 700mV
8 FUNCTION SW
(SLOW SW)
9 GND (G) Used Used
10 SCL / T-V LINK Not used Used
11 G input 700mV
12 SDA Not used Used (SDA2)
13 GND (R) Used Used
14 GND (YS) Used Not used
15 R / C input R : 700mV
16 Ys input (FAST SW) Low : 0V-0.4V, High : 1V-3V, 75 Used Used
17 GND (VIDEO output) Used Used
18 GND (VIDEO input) Used Used
19 VIDEO output 1V
20 VIDEO / Y input 1V
21 COMMON GND Used Used
500mV(rms) (Nominal),, Low impedance Used (TV OUT) Used (LINE OUT) 500mV(rms) (Nominal),, High impedance Used (R1) Used (R2) 500mV(rms) (Nominal),, Low impedance Used (TV OUT) Used (LINE OUT)
500mV(rms) (Nominal),, High impedance Used (L1) Used (L2)
, 75 Used Used
(B-W)
Low : 0V-3V High : 8V-12V, High impedance
, 75 Used Used
(B-W)
, 75
C : 300mV
(B-W)
, 75
(P-P)
(Negative sync), 75 Used (TV OUT) Used (LINE OUT)
(P-P)
(Negative sync), 75 Used Used
(P-P)
(P-P= Peak to Peak, B-W= Blanking to white peak)
[Pin assignment]
20 18 16 14 12 10 8 6 4 2
OFF TIMER
This function can set the TV to automatically turn off after a set time.
COLOUR SYSTEM
If the picture is not clear or no colour appears, change the current colour system to another colour system.
UK type(3-pin )
Used Used
(SCL2 / TV-LINK)
Used (R) Used (C2/R)
1-6 (No.YA223)
21 19 17 15 13 11 9 7 5 3 1
2.4 TECHNICAL INFORMATION
2.4.1 LCD PANEL
This unit uses the flat type panel LCD (Liquid Crystal Display) panel that occupies as little space as possible, instead of the conventional CRT (Cathode Ray Tube), as a display unit. Since the unit has the two polarizing filter that are at right angles to each other, the unit adopts "normally black" mode, where light does not pass through the polarizing filter and the screen is black when no voltage is applied to the liquid crystals.
2.4.1.1 SPECIFICATIONS
The following table shows the specifications of this unit.
Item Specifications Remarks
Displayed colour 16777216 colours 256 colours for R, G, and B
Brightness 450cd/m
2
Contrast ratio 400: 1
Response time 25ms
View angle Horizontally: 176°, Vertically: 170°
2.4.1.2 PIXEL FAULT
There are three pixel faults - bright fault , dark fault and flicker fault - that are respectively defined as follows.
BRIGHT FAULT
In this pixel fault, a cell that should not light originally is lighting on and off. For checking this pixel fault, input ALL BLACK SCREEN and find out the cell that is lighting on and off.
DARK FAULT
In this pixel fault, a cell that should light originally is not lighting or lighting with the brightness twice as brighter as originally lighting. For checking this pixel fault, input 100% of each R/G/B colour and find out the cell that is not lighting.
FLICKER FAULT
In the pixel fault, a cell that should light originally or not light originally is flashing on and off. For checking this pixel fault, input ALL BLACK SCREEN signal or 100% of each RGB colour and find out the cell that is flashing on and off.
(No.YA223)1-7
SECTION 3
DISASSEMBLY
3.1 DISASSEMBLY PROCEDURE
NOTE:
• Make sure that the power cord is disconnected from the outlet.
• Pay special attention not to break or damage the parts.
• When removing each board, remove the connectors as required. Taking notes of the connecting points (connector numbers) makes service procedure manageable.
• Make sure that there is no bent or stain on the connectors before inserting, and firmly insert the connectors.
3.1.1 REMOVING THE STAND UNIT
• Remove the TFT DOOR SOCKET / AV DOOR SOCKET. (1) Remove the 2 screws [A], then remove the FOOT TOP
COVER.
(2) Remove the 4 screws [B],then remove the STAND UNIT.
3.1.2 REMOVING THE HANDLE
• Remove the STAND UNIT. (1) Remove the 4 screws [C]. (2) Remove the HANDLE.
3.1.3 REMOVING THE BACK COVER
• Remove the STAND UNIT.
• Remove the HANDLE. (1) Remove the 5 screws [D]. (2) Remove the BACK COVER toward you.
3.1.4 REMOVING THE FAV PWB
• Remove the STAND UNIT.
• Remove the HANDLE.
• Remove the BACK COVER. (1) Remove the 2 screws [E]. (2) Remove the FAV PWB.
3.1.5 REMOVING THE BRACKET SCART
• Remove the STAND UNIT.
• Remove the HANDLE.
• Remove the BACK COVER.
• Remove the FAV PWB. (1) Remove the 2 screws [F]. (2) Remove the BRACKET SCART.
3.1.6 REMOVING THE MAIN PWB
• Remove the STAND UNIT.
• Remove the HANDLE.
• Remove the BACK COVER.
• Remove the BRACKET SCART. (1) Remove the 7 screws [G]. (2) Remove the MAIN PWB.
3.1.8 REMOVING THE INVERTER PWB / INVERTER FARME
• Remove the STAND UNIT / HANDLE & BACK COVER.
• Remove the BRACKET SOCKET, BRACKET SCART & MAIN PWB. (1) Remove the 4 screws [I], then remove the INVERTER
PWB.
(2) Remove the 4 screws [J], then remove the INVERTER
FRAME.
(3) Remove the INVERTER PWB & INVERTER FRAME.
3.1.9 REMOVING THE LCD PANEL UNIT
• Remove the STAND UNIT, HANDLE & BACK COVER.
• Remove the BRACKET SCRAT & MAIN PWB.
• Remove the MAIN FRAME & INVERTER PWB / FRAME. (1) Remove the 2 screws [K]. (2) Follow the same step when removing the other hand LCD
HOLDER.
(3) Sightly raise the both sides of the LCD PANEL by hand
from the FRONT COVER.
NOTE:
• Pay special attention not to break or damage on the LCD
PANEL face or frame.
3.1.10 REMOVING THE SPEAKERS
• Remove the STAND UNIT, HANDLE & BACK COVER. (1) Remove the 4 screws [L] from each speaker. (2) Remove the SPEAKER from the FRONT COVER. (3) Follow the same when removing the other hand speakers.
3.1.11 REMOVING THE HEADPHONE PWB
• Remove the STAND UNIT, HANDLE & BACK COVER. (1) Remove the 1 screw [M]. (2) Remove the HEADPHONE PWB from the FRONT COVER.
3.1.12 REMOVING THE LED PWB
• Remove the STAND UNIT, HANDLE & BACK COVER.
• Remove the BRACKET SOCKET, BRACKET SCART, MAIN PWB, INVERTER FRAME & MAIN FRAME. (1) Remove the 1 screw [N]. (2) Remove the LED PWB from the FRONT COVER.
3.1.7 REMOVING THE MAIN FRAME
• Remove the STAND UNIT / HANDLE & BACK COVER.
• Remove the BRACKET SOCKET & BRACKET SCART.
• Remove the MAIN PWB. (1) Remove the 7 screws [H]. (2) Remove the MAIN FRAME.
1-8 (No.YA223)
3.1.13 REMOVING THE SIDE CONTROL PWB
• Remove the LED PWB / HEADPHONE PWB. (1) Remove the 2 screws [O]. (2) Remove the SIDE CONTROL PWB with control knob. (3) Remove the SIDE CONTROL PWB from control knob.
G
MAIN PWB
MAIN FRAME
H
J
INVERTER FRAME
AV DOOR
SOCKET
HANDLE
C
F
TUNER
D
(x5)
BPACKET SCART
BACK COVER
I
INVERTER
PWB
LCD HOLDER
K
K
LCD PANEL UNIT
LCD HOLDER
BUTTON FUNCTION
O
BUTTON FUNCTION PLATE
TFT DOOR
SOCKET
A
FOOT TOP
COVER
SIDE CONTROL
FAV PWB
PWB
E
M
N
LED PWB
LENS LED
LENS IR
HEADPHONE
PWB
L
B
SPEAKE
(x4)
STAND UNIT
FRONT COVER
Fig.1
(No.YA223)1-9
3.2 REPLACEMENT OF CHIP COMPONENT
3.2.1 CAUTIONS
(1) Avoid heating for more than 3 seconds. (2) Do not rub the electrodes and the resist parts of the pattern. (3) When removing a chip part, melt the solder adequately. (4) Do not reuse a chip part after removing it.
3.2.2 SOLDERING IRON
(1) Use a high insulation soldering iron with a thin pointed end of it. (2) A 30w soldering iron is recommended for easily removing parts.
3.2.3 REPLACEMENT STEPS
1. How to remove Chip parts
2. How to install Chip parts
[Resistors, capacitors, etc.]
(1) As shown in the figure, push the part with tweezers and
alternately melt the solder at each end.
(2) Shift with the tweezers and remove the chip part.
[Transistors, diodes, variable resistors, etc.]
(1) Apply extra solder to each lead.
SOLDER
SOLDER
[Resistors, capacitors, etc.]
(1) Apply solder to the pattern as indicated in the figure.
(2) Grasp the chip part with tweezers and place it on the
solder. Then heat and melt the solder at both ends of the chip part.
[Transistors, diodes, variable resistors, etc.]
(1) Apply solder to the pattern as indicated in the figure. (2) Grasp the chip part with tweezers and place it on the
solder.
(3) First solder lead A as indicated in the figure.
(2) As shown in the figure, push the part with tweezers and
alternately melt the solder at each lead. Shift and remove the chip part.
NOTE :
After removing the part, remove remaining solder from the pattern.
1-10 (No.YA223)
A
B
C
(4) Then solder leads B and C.
A
B
C
SECTION 4
ADJUSTMENT
This service manual does not describe ADJUSTMENT.
SECTION 5
TROUBLESHOOTING
This service manual does not describe TROUBLESHOOTING.
(No.YA223)1-11
Victor Company of Japan, Limited AV & MULTIMEDIA COMPANY VIDEO DISPLAY CATEGORY 12, 3-chome, Moriya-cho, kanagawa-ku, Yokohama, kanagawa-prefecture, 221-8528, Japan
(No.YA223)
Printed in Japan
VPT
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